Brake issue with the Deuce Please Help

[TSmallwood]

Well here is my story i broke a brake hose so i ordered all new hoses.
Well i put the hoses on the truck, bled all 6 hubs took her for a ride down the road, hit the brake petal goes to the floor but truck comes to a slow stop. I found that if you pump the petal 2 to 3 times it gets stiff and the truck will stop quick.
I took the truck home and bled the brakes again truck does the same thing petal to the
floor but if you pump it 2 to 3 times the brakes work fine. I have hecked all the lines
cant find any leaks went down dirt road all lines are dry no fluid.

here is what i am using dot 5 brake fluid it is topped off.
all the lines are new and have been bled 2 times cant get any air all fluid oming out.
the brakes were working fine before the hoses were replaed. is there any special thing i nned to do.

 

[Westech]

did you bleed the master cylinders, on the air pack and the one that the petal hooks up to? make sure you start from the top down when bleeding the system and not just the wheel cylinders. try that and let us know. if you bleed everything and it still does that it could be a bad master cylinder and time for a rebuild kit in both.

 

[TSmallwood]

Can you tell me where both are located at i am new at working on the Deuce

 

[Westech]

well one is part of the air pack (brake booster) and one is hooked up to the brake petal. there are bleeders on both. start with the top (one that is hooked to the brake petal) and work your way out from there.

 

[TSmallwood]

Thanks i will try

 

[Westech]

here is a pic of the air pack

 

[KaiserM109]

When we picked up a deuce (M109A3) at Norman, OK it had no brakes. There was evidence that it has lost a lot of fluid out the right rear wheel and the master cylinder was dry. We filled the master cylinder and bled the offending wheel cylinder and we had symptoms similar to what TSmallwood is describing.

I crawled under and saw another bleeder valve on the air pack pictured above. We bled that and got a LOT of air. We bled the wheel cylinder again and that fixed the problem. We ran about a quart total through the lines. The brakes held for the 550 mile trip to Colorado. Even the wheel cylinder that had leaked in the lot started working properly. Next time we do it in the order described above.

Arlyn

 

[TSmallwood]

Beld the air pack all the hubs and still the same thing.
Petal goes (the first push) all the way to the floor the secound push goes about 4 inches to the floor then the 3rd push about 5 to 6 inches from the floor.
i did notice that there is a hose near the front passanger side right above the pto axle shaft it blows out a cloud or and a little puff then i noticed a few drips of fluid seams as if it is brake fluid any ideas.

 

[Floridianson]

If you pull down on the rubber boot on the master is there signs of BF?

 

[Westech]

sounds like rebuild time

 

[WillWagner]

Try it with one of Kennys power bleeder. I made one and it works great, did the 105 with it too. Try this first. Sounds like there is still air in the system somewhere.
http://www.steelsoldiers.com/index.php?name=PNphpBB2&file=viewtopic&t=3439

 

[TSmallwood]

Thanks guys i have tried about everything that everyone has told me but the breaks are still soft the funny thing is that the back tires will lockup during a hard break but the front do not. i tested it in a field near my house got to aout 15-20 miles per hour and slamed the brakes to the floor and the back tires dig in the dirt and the front didnt they just kept rolling (you can slide in the dirt). well i am clueless to what it could be, i have tried just about everything
the funny thing is that the brakes worked fine untill the busted hose, and the replacements.
i dont think its a air pack or any other problem with the master.

 

[bottleworks]

i tested it in a field near my house got to aout 15-20 miles per hour and slamed the brakes to the floor and the back tires dig in the dirt and the front didnt they just kept rolling (you can slide in the dirt).

Sounds like air in the front. Just how exactly are you bleeding the system?

 

[TSmallwood]

We are going by the manual open valve, 3/4 turn pump brakes 3 times, hold down on the third pump, then tighten
the bleeder. add more dot 5 and pick anoher wheel. started with the air pack.

 

[Westech]

well you want to start up to at the masters.... (foot off petal) open the bleeder, push petal to the floor, close the bleeder. no need to "pump" the brakes. you can foam the air thats in the lines by doing that and then your really F'ed. just open the bleeder.. push to floor.. close bleeder. on the wheel cylinders you are going to have to do each wheel at least 10 times.. thats alot of line you have to flush out. and yes I have done thins before and im master ASE. I think you are foaming the brake fluid and that could be your problem. try this way and let me know what s up

 

[bottleworks]

...pump brakes 3 times, hold down on the third pump, then tighten
the bleeder.

Their's your problem! Your bleeding it wrong. If you release that pedal with the bleeder open (those first 2 foot pumps), you are introducing air.

Push the pedal, open the bleeder, close the bleeder, then release the pedal. Then repeat.
Don't stop until the fluid is clear and no bubbles. After I am done bleeding, I also like to gravity bleed each bleeder. But it is not needed.

 

[swbradley1]

Interesting tips. Always get great info on the site.

I went out and drove one of Deuces around the fields and went I went to park it I noticed that the brake pedal went to the floor. I guess that's nature's way of telling me to do some brake work.

 

[KaiserM109]

... If you release that pedal with the bleeder open (those first 2 foot pumps), you are introducing air.

Push the pedal, open the bleeder, close the bleeder, then release the pedal.

The method I always use is to put a hose over the end of the bleeder to catch fluids and drain it into some type of bottle. Have a friend in the cab to operate the pedal; open the bleeder with the pedal UP, press the pedal down and hold, close the valve and release the pedal; repeat 'til your arms wear out.

I'm new to MV equipment, so take this suggestion for what it is worth. So far working on my deuce and an M105 trailer has been very similar to working on civilian 4x4s (up to 1 ton), except everything is 50% bigger: excuse to buy new, bigger tools! Also, the brakes on a deuce, being air-over-hydrolics are a big difference.

If I had that symptom on a civilian 4x4 where the pedal would pump up, I would look for a brake run-out problem. On civilian brake systems there are automatic adjustors that keep the shoes near the drum. If they fail, or are removed as happened with a Ford F100 I acquired, the shoes will take more than 1 pump to run all the way out. When they are released, it takes about 2 to 5 seconds for the shoes to collapse all the way back in. On real old brake systems it was necessary, as with my M105s, to periodically manually adjust the stops on the brake shoes' run-out. I would like to hear from guys on this web site if there is any similarity.

If the problems started with a broken hose, I would guess that the trouble really is air in the system. I can see how a lot of air would need to be compressed before the shoes would start to run out.

I am making plans to go through all my wheel assemblies to replace all old rubber such as wheel cylinder cups, hoses , etc, and get a good look at the brakes and wheel bearings. I would suggest that you plan to do the same. Most of these rigs have less than 30K miles when they come out of service, but if they have in the range of 50K, the brakes probably need serious service. I believe it was called 'S Service' in the Army in the '60s and was required once a year. Things like rubber deteriorate with time, regardless of use.

 

[Barrman]

It sounds like you have a bleeding procedure problem. But, what about brake shoe adjustment?

If the shoes are far from the drums, the first push of the pedal just gets them close and then the next push or two actaully applies the brakes. Read the manual about "major" and "minor" shoe adjustments. Practically, if you jack up any wheel, spin the tire. If you don't hear brake rub between the shoe and the drum, get an 11/16" wrench and turn the top adjust just a little down until you hear noise while the tire is spinning. Do this on each shoe and each brake. (12 adjusters) If all the air is out of your line, you will have good brakes.

The best course of action of course and the safest is to pull each drum off, check your shoes, wheel cylinders and do a proper major adjustment.

 

[FormerNewMVGuy]

Yeah , my pedal was low... so i pulled all the wheels off unbolted the axle flanges and adjusted all the brakes with my feeler guage! Now my pedal is right on top the way it should be But the system really has to bleed properly first! Most of us have built a power bleeder, makes the job so much easier!!!